Commit | Line | Data |
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6cbd5570 CM |
1 | /* |
2 | * Copyright (C) 2007 Oracle. All rights reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public | |
6 | * License v2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public | |
14 | * License along with this program; if not, write to the | |
15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
16 | * Boston, MA 021110-1307, USA. | |
17 | */ | |
18 | ||
79154b1b | 19 | #include <linux/fs.h> |
5a0e3ad6 | 20 | #include <linux/slab.h> |
34088780 | 21 | #include <linux/sched.h> |
d3c2fdcf | 22 | #include <linux/writeback.h> |
5f39d397 | 23 | #include <linux/pagemap.h> |
5f2cc086 | 24 | #include <linux/blkdev.h> |
79154b1b CM |
25 | #include "ctree.h" |
26 | #include "disk-io.h" | |
27 | #include "transaction.h" | |
925baedd | 28 | #include "locking.h" |
e02119d5 | 29 | #include "tree-log.h" |
79154b1b | 30 | |
0f7d52f4 CM |
31 | #define BTRFS_ROOT_TRANS_TAG 0 |
32 | ||
80b6794d | 33 | static noinline void put_transaction(struct btrfs_transaction *transaction) |
79154b1b | 34 | { |
13c5a93e JB |
35 | WARN_ON(atomic_read(&transaction->use_count) == 0); |
36 | if (atomic_dec_and_test(&transaction->use_count)) { | |
a4abeea4 | 37 | BUG_ON(!list_empty(&transaction->list)); |
2c90e5d6 CM |
38 | memset(transaction, 0, sizeof(*transaction)); |
39 | kmem_cache_free(btrfs_transaction_cachep, transaction); | |
78fae27e | 40 | } |
79154b1b CM |
41 | } |
42 | ||
817d52f8 JB |
43 | static noinline void switch_commit_root(struct btrfs_root *root) |
44 | { | |
817d52f8 JB |
45 | free_extent_buffer(root->commit_root); |
46 | root->commit_root = btrfs_root_node(root); | |
817d52f8 JB |
47 | } |
48 | ||
d352ac68 CM |
49 | /* |
50 | * either allocate a new transaction or hop into the existing one | |
51 | */ | |
a4abeea4 | 52 | static noinline int join_transaction(struct btrfs_root *root, int nofail) |
79154b1b CM |
53 | { |
54 | struct btrfs_transaction *cur_trans; | |
a4abeea4 JB |
55 | |
56 | spin_lock(&root->fs_info->trans_lock); | |
57 | if (root->fs_info->trans_no_join) { | |
58 | if (!nofail) { | |
59 | spin_unlock(&root->fs_info->trans_lock); | |
60 | return -EBUSY; | |
61 | } | |
62 | } | |
63 | ||
79154b1b | 64 | cur_trans = root->fs_info->running_transaction; |
a4abeea4 JB |
65 | if (cur_trans) { |
66 | atomic_inc(&cur_trans->use_count); | |
67 | atomic_inc(&cur_trans->num_writers); | |
68 | cur_trans->num_joined++; | |
69 | spin_unlock(&root->fs_info->trans_lock); | |
70 | return 0; | |
71 | } | |
72 | spin_unlock(&root->fs_info->trans_lock); | |
73 | ||
74 | cur_trans = kmem_cache_alloc(btrfs_transaction_cachep, GFP_NOFS); | |
75 | if (!cur_trans) | |
76 | return -ENOMEM; | |
77 | spin_lock(&root->fs_info->trans_lock); | |
78 | if (root->fs_info->running_transaction) { | |
79 | kmem_cache_free(btrfs_transaction_cachep, cur_trans); | |
80 | cur_trans = root->fs_info->running_transaction; | |
81 | atomic_inc(&cur_trans->use_count); | |
13c5a93e | 82 | atomic_inc(&cur_trans->num_writers); |
15ee9bc7 | 83 | cur_trans->num_joined++; |
a4abeea4 JB |
84 | spin_unlock(&root->fs_info->trans_lock); |
85 | return 0; | |
79154b1b | 86 | } |
a4abeea4 JB |
87 | atomic_set(&cur_trans->num_writers, 1); |
88 | cur_trans->num_joined = 0; | |
89 | init_waitqueue_head(&cur_trans->writer_wait); | |
90 | init_waitqueue_head(&cur_trans->commit_wait); | |
91 | cur_trans->in_commit = 0; | |
92 | cur_trans->blocked = 0; | |
93 | /* | |
94 | * One for this trans handle, one so it will live on until we | |
95 | * commit the transaction. | |
96 | */ | |
97 | atomic_set(&cur_trans->use_count, 2); | |
98 | cur_trans->commit_done = 0; | |
99 | cur_trans->start_time = get_seconds(); | |
100 | ||
101 | cur_trans->delayed_refs.root = RB_ROOT; | |
102 | cur_trans->delayed_refs.num_entries = 0; | |
103 | cur_trans->delayed_refs.num_heads_ready = 0; | |
104 | cur_trans->delayed_refs.num_heads = 0; | |
105 | cur_trans->delayed_refs.flushing = 0; | |
106 | cur_trans->delayed_refs.run_delayed_start = 0; | |
107 | spin_lock_init(&cur_trans->commit_lock); | |
108 | spin_lock_init(&cur_trans->delayed_refs.lock); | |
109 | ||
110 | INIT_LIST_HEAD(&cur_trans->pending_snapshots); | |
111 | list_add_tail(&cur_trans->list, &root->fs_info->trans_list); | |
112 | extent_io_tree_init(&cur_trans->dirty_pages, | |
113 | root->fs_info->btree_inode->i_mapping, | |
114 | GFP_NOFS); | |
115 | root->fs_info->generation++; | |
116 | cur_trans->transid = root->fs_info->generation; | |
117 | root->fs_info->running_transaction = cur_trans; | |
118 | spin_unlock(&root->fs_info->trans_lock); | |
15ee9bc7 | 119 | |
79154b1b CM |
120 | return 0; |
121 | } | |
122 | ||
d352ac68 | 123 | /* |
d397712b CM |
124 | * this does all the record keeping required to make sure that a reference |
125 | * counted root is properly recorded in a given transaction. This is required | |
126 | * to make sure the old root from before we joined the transaction is deleted | |
127 | * when the transaction commits | |
d352ac68 | 128 | */ |
a4abeea4 JB |
129 | int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans, |
130 | struct btrfs_root *root) | |
6702ed49 | 131 | { |
5d4f98a2 | 132 | if (root->ref_cows && root->last_trans < trans->transid) { |
6702ed49 | 133 | WARN_ON(root == root->fs_info->extent_root); |
5d4f98a2 YZ |
134 | WARN_ON(root->commit_root != root->node); |
135 | ||
a4abeea4 JB |
136 | spin_lock(&root->fs_info->fs_roots_radix_lock); |
137 | if (root->last_trans == trans->transid) { | |
138 | spin_unlock(&root->fs_info->fs_roots_radix_lock); | |
139 | return 0; | |
140 | } | |
141 | root->last_trans = trans->transid; | |
5d4f98a2 YZ |
142 | radix_tree_tag_set(&root->fs_info->fs_roots_radix, |
143 | (unsigned long)root->root_key.objectid, | |
144 | BTRFS_ROOT_TRANS_TAG); | |
a4abeea4 | 145 | spin_unlock(&root->fs_info->fs_roots_radix_lock); |
5d4f98a2 YZ |
146 | btrfs_init_reloc_root(trans, root); |
147 | } | |
148 | return 0; | |
149 | } | |
bcc63abb | 150 | |
d352ac68 CM |
151 | /* wait for commit against the current transaction to become unblocked |
152 | * when this is done, it is safe to start a new transaction, but the current | |
153 | * transaction might not be fully on disk. | |
154 | */ | |
37d1aeee | 155 | static void wait_current_trans(struct btrfs_root *root) |
79154b1b | 156 | { |
f9295749 | 157 | struct btrfs_transaction *cur_trans; |
79154b1b | 158 | |
a4abeea4 | 159 | spin_lock(&root->fs_info->trans_lock); |
f9295749 | 160 | cur_trans = root->fs_info->running_transaction; |
37d1aeee | 161 | if (cur_trans && cur_trans->blocked) { |
f9295749 | 162 | DEFINE_WAIT(wait); |
13c5a93e | 163 | atomic_inc(&cur_trans->use_count); |
a4abeea4 | 164 | spin_unlock(&root->fs_info->trans_lock); |
d397712b | 165 | while (1) { |
f9295749 CM |
166 | prepare_to_wait(&root->fs_info->transaction_wait, &wait, |
167 | TASK_UNINTERRUPTIBLE); | |
471fa17d | 168 | if (!cur_trans->blocked) |
f9295749 | 169 | break; |
471fa17d | 170 | schedule(); |
f9295749 | 171 | } |
471fa17d | 172 | finish_wait(&root->fs_info->transaction_wait, &wait); |
f9295749 | 173 | put_transaction(cur_trans); |
a4abeea4 JB |
174 | } else { |
175 | spin_unlock(&root->fs_info->trans_lock); | |
f9295749 | 176 | } |
37d1aeee CM |
177 | } |
178 | ||
249ac1e5 JB |
179 | enum btrfs_trans_type { |
180 | TRANS_START, | |
181 | TRANS_JOIN, | |
182 | TRANS_USERSPACE, | |
0af3d00b | 183 | TRANS_JOIN_NOLOCK, |
249ac1e5 JB |
184 | }; |
185 | ||
a22285a6 YZ |
186 | static int may_wait_transaction(struct btrfs_root *root, int type) |
187 | { | |
a4abeea4 JB |
188 | if (root->fs_info->log_root_recovering) |
189 | return 0; | |
190 | ||
191 | if (type == TRANS_USERSPACE) | |
192 | return 1; | |
193 | ||
194 | if (type == TRANS_START && | |
195 | !atomic_read(&root->fs_info->open_ioctl_trans)) | |
a22285a6 | 196 | return 1; |
a4abeea4 | 197 | |
a22285a6 YZ |
198 | return 0; |
199 | } | |
200 | ||
e02119d5 | 201 | static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root, |
a22285a6 | 202 | u64 num_items, int type) |
37d1aeee | 203 | { |
a22285a6 YZ |
204 | struct btrfs_trans_handle *h; |
205 | struct btrfs_transaction *cur_trans; | |
06d5a589 | 206 | int retries = 0; |
37d1aeee | 207 | int ret; |
acce952b | 208 | |
209 | if (root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) | |
210 | return ERR_PTR(-EROFS); | |
2a1eb461 JB |
211 | |
212 | if (current->journal_info) { | |
213 | WARN_ON(type != TRANS_JOIN && type != TRANS_JOIN_NOLOCK); | |
214 | h = current->journal_info; | |
215 | h->use_count++; | |
216 | h->orig_rsv = h->block_rsv; | |
217 | h->block_rsv = NULL; | |
218 | goto got_it; | |
219 | } | |
a22285a6 YZ |
220 | again: |
221 | h = kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS); | |
222 | if (!h) | |
223 | return ERR_PTR(-ENOMEM); | |
37d1aeee | 224 | |
a22285a6 | 225 | if (may_wait_transaction(root, type)) |
37d1aeee | 226 | wait_current_trans(root); |
a22285a6 | 227 | |
a4abeea4 JB |
228 | do { |
229 | ret = join_transaction(root, type == TRANS_JOIN_NOLOCK); | |
230 | if (ret == -EBUSY) | |
231 | wait_current_trans(root); | |
232 | } while (ret == -EBUSY); | |
233 | ||
db5b493a | 234 | if (ret < 0) { |
6e8df2ae | 235 | kmem_cache_free(btrfs_trans_handle_cachep, h); |
db5b493a TI |
236 | return ERR_PTR(ret); |
237 | } | |
0f7d52f4 | 238 | |
a22285a6 | 239 | cur_trans = root->fs_info->running_transaction; |
a22285a6 YZ |
240 | |
241 | h->transid = cur_trans->transid; | |
242 | h->transaction = cur_trans; | |
79154b1b | 243 | h->blocks_used = 0; |
d2fb3437 | 244 | h->block_group = 0; |
a22285a6 | 245 | h->bytes_reserved = 0; |
56bec294 | 246 | h->delayed_ref_updates = 0; |
2a1eb461 | 247 | h->use_count = 1; |
f0486c68 | 248 | h->block_rsv = NULL; |
2a1eb461 | 249 | h->orig_rsv = NULL; |
b7ec40d7 | 250 | |
a22285a6 YZ |
251 | smp_mb(); |
252 | if (cur_trans->blocked && may_wait_transaction(root, type)) { | |
253 | btrfs_commit_transaction(h, root); | |
254 | goto again; | |
255 | } | |
256 | ||
257 | if (num_items > 0) { | |
8bb8ab2e | 258 | ret = btrfs_trans_reserve_metadata(h, root, num_items); |
06d5a589 JB |
259 | if (ret == -EAGAIN && !retries) { |
260 | retries++; | |
a22285a6 YZ |
261 | btrfs_commit_transaction(h, root); |
262 | goto again; | |
06d5a589 JB |
263 | } else if (ret == -EAGAIN) { |
264 | /* | |
265 | * We have already retried and got EAGAIN, so really we | |
266 | * don't have space, so set ret to -ENOSPC. | |
267 | */ | |
268 | ret = -ENOSPC; | |
a22285a6 | 269 | } |
06d5a589 | 270 | |
a22285a6 YZ |
271 | if (ret < 0) { |
272 | btrfs_end_transaction(h, root); | |
273 | return ERR_PTR(ret); | |
274 | } | |
275 | } | |
9ed74f2d | 276 | |
2a1eb461 | 277 | got_it: |
a4abeea4 | 278 | btrfs_record_root_in_trans(h, root); |
a22285a6 YZ |
279 | |
280 | if (!current->journal_info && type != TRANS_USERSPACE) | |
281 | current->journal_info = h; | |
79154b1b CM |
282 | return h; |
283 | } | |
284 | ||
f9295749 | 285 | struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root, |
a22285a6 | 286 | int num_items) |
f9295749 | 287 | { |
a22285a6 | 288 | return start_transaction(root, num_items, TRANS_START); |
f9295749 | 289 | } |
7a7eaa40 | 290 | struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root) |
f9295749 | 291 | { |
a22285a6 | 292 | return start_transaction(root, 0, TRANS_JOIN); |
f9295749 CM |
293 | } |
294 | ||
7a7eaa40 | 295 | struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root) |
0af3d00b JB |
296 | { |
297 | return start_transaction(root, 0, TRANS_JOIN_NOLOCK); | |
298 | } | |
299 | ||
7a7eaa40 | 300 | struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *root) |
9ca9ee09 | 301 | { |
7a7eaa40 | 302 | return start_transaction(root, 0, TRANS_USERSPACE); |
9ca9ee09 SW |
303 | } |
304 | ||
d352ac68 | 305 | /* wait for a transaction commit to be fully complete */ |
89ce8a63 CM |
306 | static noinline int wait_for_commit(struct btrfs_root *root, |
307 | struct btrfs_transaction *commit) | |
308 | { | |
309 | DEFINE_WAIT(wait); | |
d397712b | 310 | while (!commit->commit_done) { |
89ce8a63 CM |
311 | prepare_to_wait(&commit->commit_wait, &wait, |
312 | TASK_UNINTERRUPTIBLE); | |
313 | if (commit->commit_done) | |
314 | break; | |
89ce8a63 | 315 | schedule(); |
89ce8a63 | 316 | } |
89ce8a63 CM |
317 | finish_wait(&commit->commit_wait, &wait); |
318 | return 0; | |
319 | } | |
320 | ||
46204592 SW |
321 | int btrfs_wait_for_commit(struct btrfs_root *root, u64 transid) |
322 | { | |
323 | struct btrfs_transaction *cur_trans = NULL, *t; | |
324 | int ret; | |
325 | ||
46204592 SW |
326 | ret = 0; |
327 | if (transid) { | |
328 | if (transid <= root->fs_info->last_trans_committed) | |
a4abeea4 | 329 | goto out; |
46204592 SW |
330 | |
331 | /* find specified transaction */ | |
a4abeea4 | 332 | spin_lock(&root->fs_info->trans_lock); |
46204592 SW |
333 | list_for_each_entry(t, &root->fs_info->trans_list, list) { |
334 | if (t->transid == transid) { | |
335 | cur_trans = t; | |
a4abeea4 | 336 | atomic_inc(&cur_trans->use_count); |
46204592 SW |
337 | break; |
338 | } | |
339 | if (t->transid > transid) | |
340 | break; | |
341 | } | |
a4abeea4 | 342 | spin_unlock(&root->fs_info->trans_lock); |
46204592 SW |
343 | ret = -EINVAL; |
344 | if (!cur_trans) | |
a4abeea4 | 345 | goto out; /* bad transid */ |
46204592 SW |
346 | } else { |
347 | /* find newest transaction that is committing | committed */ | |
a4abeea4 | 348 | spin_lock(&root->fs_info->trans_lock); |
46204592 SW |
349 | list_for_each_entry_reverse(t, &root->fs_info->trans_list, |
350 | list) { | |
351 | if (t->in_commit) { | |
352 | if (t->commit_done) | |
a4abeea4 | 353 | goto out; |
46204592 | 354 | cur_trans = t; |
a4abeea4 | 355 | atomic_inc(&cur_trans->use_count); |
46204592 SW |
356 | break; |
357 | } | |
358 | } | |
a4abeea4 | 359 | spin_unlock(&root->fs_info->trans_lock); |
46204592 | 360 | if (!cur_trans) |
a4abeea4 | 361 | goto out; /* nothing committing|committed */ |
46204592 SW |
362 | } |
363 | ||
46204592 SW |
364 | wait_for_commit(root, cur_trans); |
365 | ||
46204592 SW |
366 | put_transaction(cur_trans); |
367 | ret = 0; | |
a4abeea4 | 368 | out: |
46204592 SW |
369 | return ret; |
370 | } | |
371 | ||
5d4f98a2 | 372 | #if 0 |
d352ac68 | 373 | /* |
d397712b CM |
374 | * rate limit against the drop_snapshot code. This helps to slow down new |
375 | * operations if the drop_snapshot code isn't able to keep up. | |
d352ac68 | 376 | */ |
37d1aeee | 377 | static void throttle_on_drops(struct btrfs_root *root) |
ab78c84d CM |
378 | { |
379 | struct btrfs_fs_info *info = root->fs_info; | |
2dd3e67b | 380 | int harder_count = 0; |
ab78c84d | 381 | |
2dd3e67b | 382 | harder: |
ab78c84d CM |
383 | if (atomic_read(&info->throttles)) { |
384 | DEFINE_WAIT(wait); | |
385 | int thr; | |
ab78c84d CM |
386 | thr = atomic_read(&info->throttle_gen); |
387 | ||
388 | do { | |
389 | prepare_to_wait(&info->transaction_throttle, | |
390 | &wait, TASK_UNINTERRUPTIBLE); | |
391 | if (!atomic_read(&info->throttles)) { | |
392 | finish_wait(&info->transaction_throttle, &wait); | |
393 | break; | |
394 | } | |
395 | schedule(); | |
396 | finish_wait(&info->transaction_throttle, &wait); | |
397 | } while (thr == atomic_read(&info->throttle_gen)); | |
2dd3e67b CM |
398 | harder_count++; |
399 | ||
400 | if (root->fs_info->total_ref_cache_size > 1 * 1024 * 1024 && | |
401 | harder_count < 2) | |
402 | goto harder; | |
403 | ||
404 | if (root->fs_info->total_ref_cache_size > 5 * 1024 * 1024 && | |
405 | harder_count < 10) | |
406 | goto harder; | |
407 | ||
408 | if (root->fs_info->total_ref_cache_size > 10 * 1024 * 1024 && | |
409 | harder_count < 20) | |
410 | goto harder; | |
ab78c84d CM |
411 | } |
412 | } | |
5d4f98a2 | 413 | #endif |
ab78c84d | 414 | |
37d1aeee CM |
415 | void btrfs_throttle(struct btrfs_root *root) |
416 | { | |
a4abeea4 | 417 | if (!atomic_read(&root->fs_info->open_ioctl_trans)) |
9ca9ee09 | 418 | wait_current_trans(root); |
37d1aeee CM |
419 | } |
420 | ||
8929ecfa YZ |
421 | static int should_end_transaction(struct btrfs_trans_handle *trans, |
422 | struct btrfs_root *root) | |
423 | { | |
424 | int ret; | |
425 | ret = btrfs_block_rsv_check(trans, root, | |
426 | &root->fs_info->global_block_rsv, 0, 5); | |
427 | return ret ? 1 : 0; | |
428 | } | |
429 | ||
430 | int btrfs_should_end_transaction(struct btrfs_trans_handle *trans, | |
431 | struct btrfs_root *root) | |
432 | { | |
433 | struct btrfs_transaction *cur_trans = trans->transaction; | |
434 | int updates; | |
435 | ||
a4abeea4 | 436 | smp_mb(); |
8929ecfa YZ |
437 | if (cur_trans->blocked || cur_trans->delayed_refs.flushing) |
438 | return 1; | |
439 | ||
440 | updates = trans->delayed_ref_updates; | |
441 | trans->delayed_ref_updates = 0; | |
442 | if (updates) | |
443 | btrfs_run_delayed_refs(trans, root, updates); | |
444 | ||
445 | return should_end_transaction(trans, root); | |
446 | } | |
447 | ||
89ce8a63 | 448 | static int __btrfs_end_transaction(struct btrfs_trans_handle *trans, |
0af3d00b | 449 | struct btrfs_root *root, int throttle, int lock) |
79154b1b | 450 | { |
8929ecfa | 451 | struct btrfs_transaction *cur_trans = trans->transaction; |
ab78c84d | 452 | struct btrfs_fs_info *info = root->fs_info; |
c3e69d58 CM |
453 | int count = 0; |
454 | ||
2a1eb461 JB |
455 | if (--trans->use_count) { |
456 | trans->block_rsv = trans->orig_rsv; | |
457 | return 0; | |
458 | } | |
459 | ||
c3e69d58 CM |
460 | while (count < 4) { |
461 | unsigned long cur = trans->delayed_ref_updates; | |
462 | trans->delayed_ref_updates = 0; | |
463 | if (cur && | |
464 | trans->transaction->delayed_refs.num_heads_ready > 64) { | |
465 | trans->delayed_ref_updates = 0; | |
b7ec40d7 CM |
466 | |
467 | /* | |
468 | * do a full flush if the transaction is trying | |
469 | * to close | |
470 | */ | |
471 | if (trans->transaction->delayed_refs.flushing) | |
472 | cur = 0; | |
c3e69d58 CM |
473 | btrfs_run_delayed_refs(trans, root, cur); |
474 | } else { | |
475 | break; | |
476 | } | |
477 | count++; | |
56bec294 CM |
478 | } |
479 | ||
a22285a6 YZ |
480 | btrfs_trans_release_metadata(trans, root); |
481 | ||
a4abeea4 JB |
482 | if (lock && !atomic_read(&root->fs_info->open_ioctl_trans) && |
483 | should_end_transaction(trans, root)) { | |
8929ecfa | 484 | trans->transaction->blocked = 1; |
a4abeea4 JB |
485 | smp_wmb(); |
486 | } | |
8929ecfa | 487 | |
0af3d00b | 488 | if (lock && cur_trans->blocked && !cur_trans->in_commit) { |
8929ecfa YZ |
489 | if (throttle) |
490 | return btrfs_commit_transaction(trans, root); | |
491 | else | |
492 | wake_up_process(info->transaction_kthread); | |
493 | } | |
494 | ||
8929ecfa | 495 | WARN_ON(cur_trans != info->running_transaction); |
13c5a93e JB |
496 | WARN_ON(atomic_read(&cur_trans->num_writers) < 1); |
497 | atomic_dec(&cur_trans->num_writers); | |
89ce8a63 | 498 | |
99d16cbc | 499 | smp_mb(); |
79154b1b CM |
500 | if (waitqueue_active(&cur_trans->writer_wait)) |
501 | wake_up(&cur_trans->writer_wait); | |
79154b1b | 502 | put_transaction(cur_trans); |
9ed74f2d JB |
503 | |
504 | if (current->journal_info == trans) | |
505 | current->journal_info = NULL; | |
d6025579 | 506 | memset(trans, 0, sizeof(*trans)); |
2c90e5d6 | 507 | kmem_cache_free(btrfs_trans_handle_cachep, trans); |
ab78c84d | 508 | |
24bbcf04 YZ |
509 | if (throttle) |
510 | btrfs_run_delayed_iputs(root); | |
511 | ||
79154b1b CM |
512 | return 0; |
513 | } | |
514 | ||
89ce8a63 CM |
515 | int btrfs_end_transaction(struct btrfs_trans_handle *trans, |
516 | struct btrfs_root *root) | |
517 | { | |
0af3d00b | 518 | return __btrfs_end_transaction(trans, root, 0, 1); |
89ce8a63 CM |
519 | } |
520 | ||
521 | int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans, | |
522 | struct btrfs_root *root) | |
523 | { | |
0af3d00b JB |
524 | return __btrfs_end_transaction(trans, root, 1, 1); |
525 | } | |
526 | ||
527 | int btrfs_end_transaction_nolock(struct btrfs_trans_handle *trans, | |
528 | struct btrfs_root *root) | |
529 | { | |
530 | return __btrfs_end_transaction(trans, root, 0, 0); | |
89ce8a63 CM |
531 | } |
532 | ||
d352ac68 CM |
533 | /* |
534 | * when btree blocks are allocated, they have some corresponding bits set for | |
535 | * them in one of two extent_io trees. This is used to make sure all of | |
690587d1 | 536 | * those extents are sent to disk but does not wait on them |
d352ac68 | 537 | */ |
690587d1 | 538 | int btrfs_write_marked_extents(struct btrfs_root *root, |
8cef4e16 | 539 | struct extent_io_tree *dirty_pages, int mark) |
79154b1b | 540 | { |
7c4452b9 | 541 | int ret; |
777e6bd7 | 542 | int err = 0; |
7c4452b9 CM |
543 | int werr = 0; |
544 | struct page *page; | |
7c4452b9 | 545 | struct inode *btree_inode = root->fs_info->btree_inode; |
777e6bd7 | 546 | u64 start = 0; |
5f39d397 CM |
547 | u64 end; |
548 | unsigned long index; | |
7c4452b9 | 549 | |
d397712b | 550 | while (1) { |
777e6bd7 | 551 | ret = find_first_extent_bit(dirty_pages, start, &start, &end, |
8cef4e16 | 552 | mark); |
5f39d397 | 553 | if (ret) |
7c4452b9 | 554 | break; |
d397712b | 555 | while (start <= end) { |
777e6bd7 CM |
556 | cond_resched(); |
557 | ||
5f39d397 | 558 | index = start >> PAGE_CACHE_SHIFT; |
35ebb934 | 559 | start = (u64)(index + 1) << PAGE_CACHE_SHIFT; |
4bef0848 | 560 | page = find_get_page(btree_inode->i_mapping, index); |
7c4452b9 CM |
561 | if (!page) |
562 | continue; | |
4bef0848 CM |
563 | |
564 | btree_lock_page_hook(page); | |
565 | if (!page->mapping) { | |
566 | unlock_page(page); | |
567 | page_cache_release(page); | |
568 | continue; | |
569 | } | |
570 | ||
6702ed49 CM |
571 | if (PageWriteback(page)) { |
572 | if (PageDirty(page)) | |
573 | wait_on_page_writeback(page); | |
574 | else { | |
575 | unlock_page(page); | |
576 | page_cache_release(page); | |
577 | continue; | |
578 | } | |
579 | } | |
7c4452b9 CM |
580 | err = write_one_page(page, 0); |
581 | if (err) | |
582 | werr = err; | |
583 | page_cache_release(page); | |
584 | } | |
585 | } | |
690587d1 CM |
586 | if (err) |
587 | werr = err; | |
588 | return werr; | |
589 | } | |
590 | ||
591 | /* | |
592 | * when btree blocks are allocated, they have some corresponding bits set for | |
593 | * them in one of two extent_io trees. This is used to make sure all of | |
594 | * those extents are on disk for transaction or log commit. We wait | |
595 | * on all the pages and clear them from the dirty pages state tree | |
596 | */ | |
597 | int btrfs_wait_marked_extents(struct btrfs_root *root, | |
8cef4e16 | 598 | struct extent_io_tree *dirty_pages, int mark) |
690587d1 CM |
599 | { |
600 | int ret; | |
601 | int err = 0; | |
602 | int werr = 0; | |
603 | struct page *page; | |
604 | struct inode *btree_inode = root->fs_info->btree_inode; | |
605 | u64 start = 0; | |
606 | u64 end; | |
607 | unsigned long index; | |
608 | ||
d397712b | 609 | while (1) { |
8cef4e16 YZ |
610 | ret = find_first_extent_bit(dirty_pages, start, &start, &end, |
611 | mark); | |
777e6bd7 CM |
612 | if (ret) |
613 | break; | |
614 | ||
8cef4e16 | 615 | clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS); |
d397712b | 616 | while (start <= end) { |
777e6bd7 CM |
617 | index = start >> PAGE_CACHE_SHIFT; |
618 | start = (u64)(index + 1) << PAGE_CACHE_SHIFT; | |
619 | page = find_get_page(btree_inode->i_mapping, index); | |
620 | if (!page) | |
621 | continue; | |
622 | if (PageDirty(page)) { | |
4bef0848 CM |
623 | btree_lock_page_hook(page); |
624 | wait_on_page_writeback(page); | |
777e6bd7 CM |
625 | err = write_one_page(page, 0); |
626 | if (err) | |
627 | werr = err; | |
628 | } | |
105d931d | 629 | wait_on_page_writeback(page); |
777e6bd7 CM |
630 | page_cache_release(page); |
631 | cond_resched(); | |
632 | } | |
633 | } | |
7c4452b9 CM |
634 | if (err) |
635 | werr = err; | |
636 | return werr; | |
79154b1b CM |
637 | } |
638 | ||
690587d1 CM |
639 | /* |
640 | * when btree blocks are allocated, they have some corresponding bits set for | |
641 | * them in one of two extent_io trees. This is used to make sure all of | |
642 | * those extents are on disk for transaction or log commit | |
643 | */ | |
644 | int btrfs_write_and_wait_marked_extents(struct btrfs_root *root, | |
8cef4e16 | 645 | struct extent_io_tree *dirty_pages, int mark) |
690587d1 CM |
646 | { |
647 | int ret; | |
648 | int ret2; | |
649 | ||
8cef4e16 YZ |
650 | ret = btrfs_write_marked_extents(root, dirty_pages, mark); |
651 | ret2 = btrfs_wait_marked_extents(root, dirty_pages, mark); | |
690587d1 CM |
652 | return ret || ret2; |
653 | } | |
654 | ||
d0c803c4 CM |
655 | int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans, |
656 | struct btrfs_root *root) | |
657 | { | |
658 | if (!trans || !trans->transaction) { | |
659 | struct inode *btree_inode; | |
660 | btree_inode = root->fs_info->btree_inode; | |
661 | return filemap_write_and_wait(btree_inode->i_mapping); | |
662 | } | |
663 | return btrfs_write_and_wait_marked_extents(root, | |
8cef4e16 YZ |
664 | &trans->transaction->dirty_pages, |
665 | EXTENT_DIRTY); | |
d0c803c4 CM |
666 | } |
667 | ||
d352ac68 CM |
668 | /* |
669 | * this is used to update the root pointer in the tree of tree roots. | |
670 | * | |
671 | * But, in the case of the extent allocation tree, updating the root | |
672 | * pointer may allocate blocks which may change the root of the extent | |
673 | * allocation tree. | |
674 | * | |
675 | * So, this loops and repeats and makes sure the cowonly root didn't | |
676 | * change while the root pointer was being updated in the metadata. | |
677 | */ | |
0b86a832 CM |
678 | static int update_cowonly_root(struct btrfs_trans_handle *trans, |
679 | struct btrfs_root *root) | |
79154b1b CM |
680 | { |
681 | int ret; | |
0b86a832 | 682 | u64 old_root_bytenr; |
86b9f2ec | 683 | u64 old_root_used; |
0b86a832 | 684 | struct btrfs_root *tree_root = root->fs_info->tree_root; |
79154b1b | 685 | |
86b9f2ec | 686 | old_root_used = btrfs_root_used(&root->root_item); |
0b86a832 | 687 | btrfs_write_dirty_block_groups(trans, root); |
56bec294 | 688 | |
d397712b | 689 | while (1) { |
0b86a832 | 690 | old_root_bytenr = btrfs_root_bytenr(&root->root_item); |
86b9f2ec YZ |
691 | if (old_root_bytenr == root->node->start && |
692 | old_root_used == btrfs_root_used(&root->root_item)) | |
79154b1b | 693 | break; |
87ef2bb4 | 694 | |
5d4f98a2 | 695 | btrfs_set_root_node(&root->root_item, root->node); |
79154b1b | 696 | ret = btrfs_update_root(trans, tree_root, |
0b86a832 CM |
697 | &root->root_key, |
698 | &root->root_item); | |
79154b1b | 699 | BUG_ON(ret); |
56bec294 | 700 | |
86b9f2ec | 701 | old_root_used = btrfs_root_used(&root->root_item); |
4a8c9a62 | 702 | ret = btrfs_write_dirty_block_groups(trans, root); |
56bec294 | 703 | BUG_ON(ret); |
0b86a832 | 704 | } |
276e680d YZ |
705 | |
706 | if (root != root->fs_info->extent_root) | |
707 | switch_commit_root(root); | |
708 | ||
0b86a832 CM |
709 | return 0; |
710 | } | |
711 | ||
d352ac68 CM |
712 | /* |
713 | * update all the cowonly tree roots on disk | |
714 | */ | |
5d4f98a2 YZ |
715 | static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans, |
716 | struct btrfs_root *root) | |
0b86a832 CM |
717 | { |
718 | struct btrfs_fs_info *fs_info = root->fs_info; | |
719 | struct list_head *next; | |
84234f3a | 720 | struct extent_buffer *eb; |
56bec294 | 721 | int ret; |
84234f3a | 722 | |
56bec294 CM |
723 | ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1); |
724 | BUG_ON(ret); | |
87ef2bb4 | 725 | |
84234f3a | 726 | eb = btrfs_lock_root_node(fs_info->tree_root); |
9fa8cfe7 | 727 | btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb); |
84234f3a YZ |
728 | btrfs_tree_unlock(eb); |
729 | free_extent_buffer(eb); | |
0b86a832 | 730 | |
56bec294 CM |
731 | ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1); |
732 | BUG_ON(ret); | |
87ef2bb4 | 733 | |
d397712b | 734 | while (!list_empty(&fs_info->dirty_cowonly_roots)) { |
0b86a832 CM |
735 | next = fs_info->dirty_cowonly_roots.next; |
736 | list_del_init(next); | |
737 | root = list_entry(next, struct btrfs_root, dirty_list); | |
87ef2bb4 | 738 | |
0b86a832 | 739 | update_cowonly_root(trans, root); |
79154b1b | 740 | } |
276e680d YZ |
741 | |
742 | down_write(&fs_info->extent_commit_sem); | |
743 | switch_commit_root(fs_info->extent_root); | |
744 | up_write(&fs_info->extent_commit_sem); | |
745 | ||
79154b1b CM |
746 | return 0; |
747 | } | |
748 | ||
d352ac68 CM |
749 | /* |
750 | * dead roots are old snapshots that need to be deleted. This allocates | |
751 | * a dirty root struct and adds it into the list of dead roots that need to | |
752 | * be deleted | |
753 | */ | |
5d4f98a2 | 754 | int btrfs_add_dead_root(struct btrfs_root *root) |
5eda7b5e | 755 | { |
a4abeea4 | 756 | spin_lock(&root->fs_info->trans_lock); |
5d4f98a2 | 757 | list_add(&root->root_list, &root->fs_info->dead_roots); |
a4abeea4 | 758 | spin_unlock(&root->fs_info->trans_lock); |
5eda7b5e CM |
759 | return 0; |
760 | } | |
761 | ||
d352ac68 | 762 | /* |
5d4f98a2 | 763 | * update all the cowonly tree roots on disk |
d352ac68 | 764 | */ |
5d4f98a2 YZ |
765 | static noinline int commit_fs_roots(struct btrfs_trans_handle *trans, |
766 | struct btrfs_root *root) | |
0f7d52f4 | 767 | { |
0f7d52f4 | 768 | struct btrfs_root *gang[8]; |
5d4f98a2 | 769 | struct btrfs_fs_info *fs_info = root->fs_info; |
0f7d52f4 CM |
770 | int i; |
771 | int ret; | |
54aa1f4d CM |
772 | int err = 0; |
773 | ||
a4abeea4 | 774 | spin_lock(&fs_info->fs_roots_radix_lock); |
d397712b | 775 | while (1) { |
5d4f98a2 YZ |
776 | ret = radix_tree_gang_lookup_tag(&fs_info->fs_roots_radix, |
777 | (void **)gang, 0, | |
0f7d52f4 CM |
778 | ARRAY_SIZE(gang), |
779 | BTRFS_ROOT_TRANS_TAG); | |
780 | if (ret == 0) | |
781 | break; | |
782 | for (i = 0; i < ret; i++) { | |
783 | root = gang[i]; | |
5d4f98a2 YZ |
784 | radix_tree_tag_clear(&fs_info->fs_roots_radix, |
785 | (unsigned long)root->root_key.objectid, | |
786 | BTRFS_ROOT_TRANS_TAG); | |
a4abeea4 | 787 | spin_unlock(&fs_info->fs_roots_radix_lock); |
31153d81 | 788 | |
e02119d5 | 789 | btrfs_free_log(trans, root); |
5d4f98a2 | 790 | btrfs_update_reloc_root(trans, root); |
d68fc57b | 791 | btrfs_orphan_commit_root(trans, root); |
bcc63abb | 792 | |
978d910d | 793 | if (root->commit_root != root->node) { |
817d52f8 | 794 | switch_commit_root(root); |
978d910d YZ |
795 | btrfs_set_root_node(&root->root_item, |
796 | root->node); | |
797 | } | |
5d4f98a2 | 798 | |
5d4f98a2 | 799 | err = btrfs_update_root(trans, fs_info->tree_root, |
0f7d52f4 CM |
800 | &root->root_key, |
801 | &root->root_item); | |
a4abeea4 | 802 | spin_lock(&fs_info->fs_roots_radix_lock); |
54aa1f4d CM |
803 | if (err) |
804 | break; | |
0f7d52f4 CM |
805 | } |
806 | } | |
a4abeea4 | 807 | spin_unlock(&fs_info->fs_roots_radix_lock); |
54aa1f4d | 808 | return err; |
0f7d52f4 CM |
809 | } |
810 | ||
d352ac68 CM |
811 | /* |
812 | * defrag a given btree. If cacheonly == 1, this won't read from the disk, | |
813 | * otherwise every leaf in the btree is read and defragged. | |
814 | */ | |
e9d0b13b CM |
815 | int btrfs_defrag_root(struct btrfs_root *root, int cacheonly) |
816 | { | |
817 | struct btrfs_fs_info *info = root->fs_info; | |
e9d0b13b | 818 | struct btrfs_trans_handle *trans; |
8929ecfa | 819 | int ret; |
d3c2fdcf | 820 | unsigned long nr; |
e9d0b13b | 821 | |
8929ecfa | 822 | if (xchg(&root->defrag_running, 1)) |
e9d0b13b | 823 | return 0; |
8929ecfa | 824 | |
6b80053d | 825 | while (1) { |
8929ecfa YZ |
826 | trans = btrfs_start_transaction(root, 0); |
827 | if (IS_ERR(trans)) | |
828 | return PTR_ERR(trans); | |
829 | ||
e9d0b13b | 830 | ret = btrfs_defrag_leaves(trans, root, cacheonly); |
8929ecfa | 831 | |
d3c2fdcf | 832 | nr = trans->blocks_used; |
e9d0b13b | 833 | btrfs_end_transaction(trans, root); |
d3c2fdcf | 834 | btrfs_btree_balance_dirty(info->tree_root, nr); |
e9d0b13b CM |
835 | cond_resched(); |
836 | ||
3f157a2f | 837 | if (root->fs_info->closing || ret != -EAGAIN) |
e9d0b13b CM |
838 | break; |
839 | } | |
840 | root->defrag_running = 0; | |
8929ecfa | 841 | return ret; |
e9d0b13b CM |
842 | } |
843 | ||
2c47e605 | 844 | #if 0 |
b7ec40d7 CM |
845 | /* |
846 | * when dropping snapshots, we generate a ton of delayed refs, and it makes | |
847 | * sense not to join the transaction while it is trying to flush the current | |
848 | * queue of delayed refs out. | |
849 | * | |
850 | * This is used by the drop snapshot code only | |
851 | */ | |
852 | static noinline int wait_transaction_pre_flush(struct btrfs_fs_info *info) | |
853 | { | |
854 | DEFINE_WAIT(wait); | |
855 | ||
856 | mutex_lock(&info->trans_mutex); | |
857 | while (info->running_transaction && | |
858 | info->running_transaction->delayed_refs.flushing) { | |
859 | prepare_to_wait(&info->transaction_wait, &wait, | |
860 | TASK_UNINTERRUPTIBLE); | |
861 | mutex_unlock(&info->trans_mutex); | |
59bc5c75 | 862 | |
b7ec40d7 | 863 | schedule(); |
59bc5c75 | 864 | |
b7ec40d7 CM |
865 | mutex_lock(&info->trans_mutex); |
866 | finish_wait(&info->transaction_wait, &wait); | |
867 | } | |
868 | mutex_unlock(&info->trans_mutex); | |
869 | return 0; | |
870 | } | |
871 | ||
d352ac68 CM |
872 | /* |
873 | * Given a list of roots that need to be deleted, call btrfs_drop_snapshot on | |
874 | * all of them | |
875 | */ | |
5d4f98a2 | 876 | int btrfs_drop_dead_root(struct btrfs_root *root) |
0f7d52f4 | 877 | { |
0f7d52f4 | 878 | struct btrfs_trans_handle *trans; |
5d4f98a2 | 879 | struct btrfs_root *tree_root = root->fs_info->tree_root; |
d3c2fdcf | 880 | unsigned long nr; |
5d4f98a2 | 881 | int ret; |
58176a96 | 882 | |
5d4f98a2 YZ |
883 | while (1) { |
884 | /* | |
885 | * we don't want to jump in and create a bunch of | |
886 | * delayed refs if the transaction is starting to close | |
887 | */ | |
888 | wait_transaction_pre_flush(tree_root->fs_info); | |
889 | trans = btrfs_start_transaction(tree_root, 1); | |
a2135011 | 890 | |
5d4f98a2 YZ |
891 | /* |
892 | * we've joined a transaction, make sure it isn't | |
893 | * closing right now | |
894 | */ | |
895 | if (trans->transaction->delayed_refs.flushing) { | |
896 | btrfs_end_transaction(trans, tree_root); | |
897 | continue; | |
9f3a7427 | 898 | } |
58176a96 | 899 | |
5d4f98a2 YZ |
900 | ret = btrfs_drop_snapshot(trans, root); |
901 | if (ret != -EAGAIN) | |
902 | break; | |
a2135011 | 903 | |
5d4f98a2 YZ |
904 | ret = btrfs_update_root(trans, tree_root, |
905 | &root->root_key, | |
906 | &root->root_item); | |
907 | if (ret) | |
54aa1f4d | 908 | break; |
bcc63abb | 909 | |
d3c2fdcf | 910 | nr = trans->blocks_used; |
0f7d52f4 CM |
911 | ret = btrfs_end_transaction(trans, tree_root); |
912 | BUG_ON(ret); | |
5eda7b5e | 913 | |
d3c2fdcf | 914 | btrfs_btree_balance_dirty(tree_root, nr); |
4dc11904 | 915 | cond_resched(); |
0f7d52f4 | 916 | } |
5d4f98a2 YZ |
917 | BUG_ON(ret); |
918 | ||
919 | ret = btrfs_del_root(trans, tree_root, &root->root_key); | |
920 | BUG_ON(ret); | |
921 | ||
922 | nr = trans->blocks_used; | |
923 | ret = btrfs_end_transaction(trans, tree_root); | |
924 | BUG_ON(ret); | |
925 | ||
926 | free_extent_buffer(root->node); | |
927 | free_extent_buffer(root->commit_root); | |
928 | kfree(root); | |
929 | ||
930 | btrfs_btree_balance_dirty(tree_root, nr); | |
54aa1f4d | 931 | return ret; |
0f7d52f4 | 932 | } |
2c47e605 | 933 | #endif |
0f7d52f4 | 934 | |
d352ac68 CM |
935 | /* |
936 | * new snapshots need to be created at a very specific time in the | |
937 | * transaction commit. This does the actual creation | |
938 | */ | |
80b6794d | 939 | static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, |
3063d29f CM |
940 | struct btrfs_fs_info *fs_info, |
941 | struct btrfs_pending_snapshot *pending) | |
942 | { | |
943 | struct btrfs_key key; | |
80b6794d | 944 | struct btrfs_root_item *new_root_item; |
3063d29f CM |
945 | struct btrfs_root *tree_root = fs_info->tree_root; |
946 | struct btrfs_root *root = pending->root; | |
6bdb72de SW |
947 | struct btrfs_root *parent_root; |
948 | struct inode *parent_inode; | |
6a912213 | 949 | struct dentry *parent; |
a22285a6 | 950 | struct dentry *dentry; |
3063d29f | 951 | struct extent_buffer *tmp; |
925baedd | 952 | struct extent_buffer *old; |
3063d29f | 953 | int ret; |
d68fc57b | 954 | u64 to_reserve = 0; |
6bdb72de | 955 | u64 index = 0; |
a22285a6 | 956 | u64 objectid; |
b83cc969 | 957 | u64 root_flags; |
3063d29f | 958 | |
80b6794d CM |
959 | new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS); |
960 | if (!new_root_item) { | |
a22285a6 | 961 | pending->error = -ENOMEM; |
80b6794d CM |
962 | goto fail; |
963 | } | |
a22285a6 | 964 | |
3063d29f | 965 | ret = btrfs_find_free_objectid(trans, tree_root, 0, &objectid); |
a22285a6 YZ |
966 | if (ret) { |
967 | pending->error = ret; | |
3063d29f | 968 | goto fail; |
a22285a6 | 969 | } |
3063d29f | 970 | |
3fd0a558 | 971 | btrfs_reloc_pre_snapshot(trans, pending, &to_reserve); |
d68fc57b YZ |
972 | btrfs_orphan_pre_snapshot(trans, pending, &to_reserve); |
973 | ||
974 | if (to_reserve > 0) { | |
975 | ret = btrfs_block_rsv_add(trans, root, &pending->block_rsv, | |
8bb8ab2e | 976 | to_reserve); |
d68fc57b YZ |
977 | if (ret) { |
978 | pending->error = ret; | |
979 | goto fail; | |
980 | } | |
981 | } | |
982 | ||
3063d29f | 983 | key.objectid = objectid; |
a22285a6 YZ |
984 | key.offset = (u64)-1; |
985 | key.type = BTRFS_ROOT_ITEM_KEY; | |
3063d29f | 986 | |
a22285a6 | 987 | trans->block_rsv = &pending->block_rsv; |
3de4586c | 988 | |
a22285a6 | 989 | dentry = pending->dentry; |
6a912213 JB |
990 | parent = dget_parent(dentry); |
991 | parent_inode = parent->d_inode; | |
a22285a6 | 992 | parent_root = BTRFS_I(parent_inode)->root; |
a4abeea4 | 993 | btrfs_record_root_in_trans(trans, parent_root); |
a22285a6 | 994 | |
3063d29f CM |
995 | /* |
996 | * insert the directory item | |
997 | */ | |
3de4586c | 998 | ret = btrfs_set_inode_index(parent_inode, &index); |
6bdb72de | 999 | BUG_ON(ret); |
0660b5af | 1000 | ret = btrfs_insert_dir_item(trans, parent_root, |
a22285a6 YZ |
1001 | dentry->d_name.name, dentry->d_name.len, |
1002 | parent_inode->i_ino, &key, | |
1003 | BTRFS_FT_DIR, index); | |
6bdb72de | 1004 | BUG_ON(ret); |
0660b5af | 1005 | |
a22285a6 YZ |
1006 | btrfs_i_size_write(parent_inode, parent_inode->i_size + |
1007 | dentry->d_name.len * 2); | |
52c26179 YZ |
1008 | ret = btrfs_update_inode(trans, parent_root, parent_inode); |
1009 | BUG_ON(ret); | |
1010 | ||
a4abeea4 | 1011 | btrfs_record_root_in_trans(trans, root); |
6bdb72de SW |
1012 | btrfs_set_root_last_snapshot(&root->root_item, trans->transid); |
1013 | memcpy(new_root_item, &root->root_item, sizeof(*new_root_item)); | |
08fe4db1 | 1014 | btrfs_check_and_init_root_item(new_root_item); |
6bdb72de | 1015 | |
b83cc969 LZ |
1016 | root_flags = btrfs_root_flags(new_root_item); |
1017 | if (pending->readonly) | |
1018 | root_flags |= BTRFS_ROOT_SUBVOL_RDONLY; | |
1019 | else | |
1020 | root_flags &= ~BTRFS_ROOT_SUBVOL_RDONLY; | |
1021 | btrfs_set_root_flags(new_root_item, root_flags); | |
1022 | ||
6bdb72de SW |
1023 | old = btrfs_lock_root_node(root); |
1024 | btrfs_cow_block(trans, root, old, NULL, 0, &old); | |
1025 | btrfs_set_lock_blocking(old); | |
1026 | ||
1027 | btrfs_copy_root(trans, root, old, &tmp, objectid); | |
1028 | btrfs_tree_unlock(old); | |
1029 | free_extent_buffer(old); | |
1030 | ||
1031 | btrfs_set_root_node(new_root_item, tmp); | |
a22285a6 YZ |
1032 | /* record when the snapshot was created in key.offset */ |
1033 | key.offset = trans->transid; | |
1034 | ret = btrfs_insert_root(trans, tree_root, &key, new_root_item); | |
6bdb72de SW |
1035 | btrfs_tree_unlock(tmp); |
1036 | free_extent_buffer(tmp); | |
a22285a6 | 1037 | BUG_ON(ret); |
6bdb72de | 1038 | |
a22285a6 YZ |
1039 | /* |
1040 | * insert root back/forward references | |
1041 | */ | |
1042 | ret = btrfs_add_root_ref(trans, tree_root, objectid, | |
0660b5af | 1043 | parent_root->root_key.objectid, |
a22285a6 YZ |
1044 | parent_inode->i_ino, index, |
1045 | dentry->d_name.name, dentry->d_name.len); | |
0660b5af | 1046 | BUG_ON(ret); |
6a912213 | 1047 | dput(parent); |
0660b5af | 1048 | |
a22285a6 YZ |
1049 | key.offset = (u64)-1; |
1050 | pending->snap = btrfs_read_fs_root_no_name(root->fs_info, &key); | |
1051 | BUG_ON(IS_ERR(pending->snap)); | |
d68fc57b | 1052 | |
3fd0a558 | 1053 | btrfs_reloc_post_snapshot(trans, pending); |
d68fc57b | 1054 | btrfs_orphan_post_snapshot(trans, pending); |
3063d29f | 1055 | fail: |
6bdb72de | 1056 | kfree(new_root_item); |
a22285a6 YZ |
1057 | btrfs_block_rsv_release(root, &pending->block_rsv, (u64)-1); |
1058 | return 0; | |
3063d29f CM |
1059 | } |
1060 | ||
d352ac68 CM |
1061 | /* |
1062 | * create all the snapshots we've scheduled for creation | |
1063 | */ | |
80b6794d CM |
1064 | static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans, |
1065 | struct btrfs_fs_info *fs_info) | |
3de4586c CM |
1066 | { |
1067 | struct btrfs_pending_snapshot *pending; | |
1068 | struct list_head *head = &trans->transaction->pending_snapshots; | |
3de4586c CM |
1069 | int ret; |
1070 | ||
c6e30871 | 1071 | list_for_each_entry(pending, head, list) { |
3de4586c CM |
1072 | ret = create_pending_snapshot(trans, fs_info, pending); |
1073 | BUG_ON(ret); | |
1074 | } | |
1075 | return 0; | |
1076 | } | |
1077 | ||
5d4f98a2 YZ |
1078 | static void update_super_roots(struct btrfs_root *root) |
1079 | { | |
1080 | struct btrfs_root_item *root_item; | |
1081 | struct btrfs_super_block *super; | |
1082 | ||
1083 | super = &root->fs_info->super_copy; | |
1084 | ||
1085 | root_item = &root->fs_info->chunk_root->root_item; | |
1086 | super->chunk_root = root_item->bytenr; | |
1087 | super->chunk_root_generation = root_item->generation; | |
1088 | super->chunk_root_level = root_item->level; | |
1089 | ||
1090 | root_item = &root->fs_info->tree_root->root_item; | |
1091 | super->root = root_item->bytenr; | |
1092 | super->generation = root_item->generation; | |
1093 | super->root_level = root_item->level; | |
0af3d00b JB |
1094 | if (super->cache_generation != 0 || btrfs_test_opt(root, SPACE_CACHE)) |
1095 | super->cache_generation = root_item->generation; | |
5d4f98a2 YZ |
1096 | } |
1097 | ||
f36f3042 CM |
1098 | int btrfs_transaction_in_commit(struct btrfs_fs_info *info) |
1099 | { | |
1100 | int ret = 0; | |
a4abeea4 | 1101 | spin_lock(&info->trans_lock); |
f36f3042 CM |
1102 | if (info->running_transaction) |
1103 | ret = info->running_transaction->in_commit; | |
a4abeea4 | 1104 | spin_unlock(&info->trans_lock); |
f36f3042 CM |
1105 | return ret; |
1106 | } | |
1107 | ||
8929ecfa YZ |
1108 | int btrfs_transaction_blocked(struct btrfs_fs_info *info) |
1109 | { | |
1110 | int ret = 0; | |
a4abeea4 | 1111 | spin_lock(&info->trans_lock); |
8929ecfa YZ |
1112 | if (info->running_transaction) |
1113 | ret = info->running_transaction->blocked; | |
a4abeea4 | 1114 | spin_unlock(&info->trans_lock); |
8929ecfa YZ |
1115 | return ret; |
1116 | } | |
1117 | ||
bb9c12c9 SW |
1118 | /* |
1119 | * wait for the current transaction commit to start and block subsequent | |
1120 | * transaction joins | |
1121 | */ | |
1122 | static void wait_current_trans_commit_start(struct btrfs_root *root, | |
1123 | struct btrfs_transaction *trans) | |
1124 | { | |
1125 | DEFINE_WAIT(wait); | |
1126 | ||
1127 | if (trans->in_commit) | |
1128 | return; | |
1129 | ||
1130 | while (1) { | |
1131 | prepare_to_wait(&root->fs_info->transaction_blocked_wait, &wait, | |
1132 | TASK_UNINTERRUPTIBLE); | |
1133 | if (trans->in_commit) { | |
1134 | finish_wait(&root->fs_info->transaction_blocked_wait, | |
1135 | &wait); | |
1136 | break; | |
1137 | } | |
bb9c12c9 | 1138 | schedule(); |
bb9c12c9 SW |
1139 | finish_wait(&root->fs_info->transaction_blocked_wait, &wait); |
1140 | } | |
1141 | } | |
1142 | ||
1143 | /* | |
1144 | * wait for the current transaction to start and then become unblocked. | |
1145 | * caller holds ref. | |
1146 | */ | |
1147 | static void wait_current_trans_commit_start_and_unblock(struct btrfs_root *root, | |
1148 | struct btrfs_transaction *trans) | |
1149 | { | |
1150 | DEFINE_WAIT(wait); | |
1151 | ||
1152 | if (trans->commit_done || (trans->in_commit && !trans->blocked)) | |
1153 | return; | |
1154 | ||
1155 | while (1) { | |
1156 | prepare_to_wait(&root->fs_info->transaction_wait, &wait, | |
1157 | TASK_UNINTERRUPTIBLE); | |
1158 | if (trans->commit_done || | |
1159 | (trans->in_commit && !trans->blocked)) { | |
1160 | finish_wait(&root->fs_info->transaction_wait, | |
1161 | &wait); | |
1162 | break; | |
1163 | } | |
bb9c12c9 | 1164 | schedule(); |
bb9c12c9 SW |
1165 | finish_wait(&root->fs_info->transaction_wait, |
1166 | &wait); | |
1167 | } | |
1168 | } | |
1169 | ||
1170 | /* | |
1171 | * commit transactions asynchronously. once btrfs_commit_transaction_async | |
1172 | * returns, any subsequent transaction will not be allowed to join. | |
1173 | */ | |
1174 | struct btrfs_async_commit { | |
1175 | struct btrfs_trans_handle *newtrans; | |
1176 | struct btrfs_root *root; | |
1177 | struct delayed_work work; | |
1178 | }; | |
1179 | ||
1180 | static void do_async_commit(struct work_struct *work) | |
1181 | { | |
1182 | struct btrfs_async_commit *ac = | |
1183 | container_of(work, struct btrfs_async_commit, work.work); | |
1184 | ||
1185 | btrfs_commit_transaction(ac->newtrans, ac->root); | |
1186 | kfree(ac); | |
1187 | } | |
1188 | ||
1189 | int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans, | |
1190 | struct btrfs_root *root, | |
1191 | int wait_for_unblock) | |
1192 | { | |
1193 | struct btrfs_async_commit *ac; | |
1194 | struct btrfs_transaction *cur_trans; | |
1195 | ||
1196 | ac = kmalloc(sizeof(*ac), GFP_NOFS); | |
db5b493a TI |
1197 | if (!ac) |
1198 | return -ENOMEM; | |
bb9c12c9 SW |
1199 | |
1200 | INIT_DELAYED_WORK(&ac->work, do_async_commit); | |
1201 | ac->root = root; | |
7a7eaa40 | 1202 | ac->newtrans = btrfs_join_transaction(root); |
3612b495 TI |
1203 | if (IS_ERR(ac->newtrans)) { |
1204 | int err = PTR_ERR(ac->newtrans); | |
1205 | kfree(ac); | |
1206 | return err; | |
1207 | } | |
bb9c12c9 SW |
1208 | |
1209 | /* take transaction reference */ | |
bb9c12c9 | 1210 | cur_trans = trans->transaction; |
13c5a93e | 1211 | atomic_inc(&cur_trans->use_count); |
bb9c12c9 SW |
1212 | |
1213 | btrfs_end_transaction(trans, root); | |
1214 | schedule_delayed_work(&ac->work, 0); | |
1215 | ||
1216 | /* wait for transaction to start and unblock */ | |
bb9c12c9 SW |
1217 | if (wait_for_unblock) |
1218 | wait_current_trans_commit_start_and_unblock(root, cur_trans); | |
1219 | else | |
1220 | wait_current_trans_commit_start(root, cur_trans); | |
1221 | put_transaction(cur_trans); | |
bb9c12c9 SW |
1222 | |
1223 | return 0; | |
1224 | } | |
1225 | ||
1226 | /* | |
1227 | * btrfs_transaction state sequence: | |
1228 | * in_commit = 0, blocked = 0 (initial) | |
1229 | * in_commit = 1, blocked = 1 | |
1230 | * blocked = 0 | |
1231 | * commit_done = 1 | |
1232 | */ | |
79154b1b CM |
1233 | int btrfs_commit_transaction(struct btrfs_trans_handle *trans, |
1234 | struct btrfs_root *root) | |
1235 | { | |
15ee9bc7 | 1236 | unsigned long joined = 0; |
79154b1b | 1237 | struct btrfs_transaction *cur_trans; |
8fd17795 | 1238 | struct btrfs_transaction *prev_trans = NULL; |
79154b1b | 1239 | DEFINE_WAIT(wait); |
15ee9bc7 | 1240 | int ret; |
89573b9c CM |
1241 | int should_grow = 0; |
1242 | unsigned long now = get_seconds(); | |
dccae999 | 1243 | int flush_on_commit = btrfs_test_opt(root, FLUSHONCOMMIT); |
79154b1b | 1244 | |
5a3f23d5 CM |
1245 | btrfs_run_ordered_operations(root, 0); |
1246 | ||
56bec294 CM |
1247 | /* make a pass through all the delayed refs we have so far |
1248 | * any runnings procs may add more while we are here | |
1249 | */ | |
1250 | ret = btrfs_run_delayed_refs(trans, root, 0); | |
1251 | BUG_ON(ret); | |
1252 | ||
a22285a6 YZ |
1253 | btrfs_trans_release_metadata(trans, root); |
1254 | ||
b7ec40d7 | 1255 | cur_trans = trans->transaction; |
56bec294 CM |
1256 | /* |
1257 | * set the flushing flag so procs in this transaction have to | |
1258 | * start sending their work down. | |
1259 | */ | |
b7ec40d7 | 1260 | cur_trans->delayed_refs.flushing = 1; |
56bec294 | 1261 | |
c3e69d58 | 1262 | ret = btrfs_run_delayed_refs(trans, root, 0); |
56bec294 CM |
1263 | BUG_ON(ret); |
1264 | ||
a4abeea4 | 1265 | spin_lock(&cur_trans->commit_lock); |
b7ec40d7 | 1266 | if (cur_trans->in_commit) { |
a4abeea4 | 1267 | spin_unlock(&cur_trans->commit_lock); |
13c5a93e | 1268 | atomic_inc(&cur_trans->use_count); |
79154b1b | 1269 | btrfs_end_transaction(trans, root); |
ccd467d6 | 1270 | |
79154b1b CM |
1271 | ret = wait_for_commit(root, cur_trans); |
1272 | BUG_ON(ret); | |
15ee9bc7 | 1273 | |
79154b1b | 1274 | put_transaction(cur_trans); |
15ee9bc7 | 1275 | |
79154b1b CM |
1276 | return 0; |
1277 | } | |
4313b399 | 1278 | |
2c90e5d6 | 1279 | trans->transaction->in_commit = 1; |
f9295749 | 1280 | trans->transaction->blocked = 1; |
a4abeea4 | 1281 | spin_unlock(&cur_trans->commit_lock); |
bb9c12c9 SW |
1282 | wake_up(&root->fs_info->transaction_blocked_wait); |
1283 | ||
a4abeea4 | 1284 | spin_lock(&root->fs_info->trans_lock); |
ccd467d6 CM |
1285 | if (cur_trans->list.prev != &root->fs_info->trans_list) { |
1286 | prev_trans = list_entry(cur_trans->list.prev, | |
1287 | struct btrfs_transaction, list); | |
1288 | if (!prev_trans->commit_done) { | |
13c5a93e | 1289 | atomic_inc(&prev_trans->use_count); |
a4abeea4 | 1290 | spin_unlock(&root->fs_info->trans_lock); |
ccd467d6 CM |
1291 | |
1292 | wait_for_commit(root, prev_trans); | |
ccd467d6 | 1293 | |
15ee9bc7 | 1294 | put_transaction(prev_trans); |
a4abeea4 JB |
1295 | } else { |
1296 | spin_unlock(&root->fs_info->trans_lock); | |
ccd467d6 | 1297 | } |
a4abeea4 JB |
1298 | } else { |
1299 | spin_unlock(&root->fs_info->trans_lock); | |
ccd467d6 | 1300 | } |
15ee9bc7 | 1301 | |
89573b9c CM |
1302 | if (now < cur_trans->start_time || now - cur_trans->start_time < 1) |
1303 | should_grow = 1; | |
1304 | ||
15ee9bc7 | 1305 | do { |
7ea394f1 | 1306 | int snap_pending = 0; |
a4abeea4 | 1307 | |
15ee9bc7 | 1308 | joined = cur_trans->num_joined; |
7ea394f1 YZ |
1309 | if (!list_empty(&trans->transaction->pending_snapshots)) |
1310 | snap_pending = 1; | |
1311 | ||
2c90e5d6 | 1312 | WARN_ON(cur_trans != trans->transaction); |
15ee9bc7 | 1313 | |
0bdb1db2 | 1314 | if (flush_on_commit || snap_pending) { |
24bbcf04 YZ |
1315 | btrfs_start_delalloc_inodes(root, 1); |
1316 | ret = btrfs_wait_ordered_extents(root, 0, 1); | |
ebecd3d9 | 1317 | BUG_ON(ret); |
7ea394f1 YZ |
1318 | } |
1319 | ||
5a3f23d5 CM |
1320 | /* |
1321 | * rename don't use btrfs_join_transaction, so, once we | |
1322 | * set the transaction to blocked above, we aren't going | |
1323 | * to get any new ordered operations. We can safely run | |
1324 | * it here and no for sure that nothing new will be added | |
1325 | * to the list | |
1326 | */ | |
1327 | btrfs_run_ordered_operations(root, 1); | |
1328 | ||
ed3b3d31 CM |
1329 | prepare_to_wait(&cur_trans->writer_wait, &wait, |
1330 | TASK_UNINTERRUPTIBLE); | |
1331 | ||
13c5a93e | 1332 | if (atomic_read(&cur_trans->num_writers) > 1) |
99d16cbc SW |
1333 | schedule_timeout(MAX_SCHEDULE_TIMEOUT); |
1334 | else if (should_grow) | |
1335 | schedule_timeout(1); | |
15ee9bc7 | 1336 | |
15ee9bc7 | 1337 | finish_wait(&cur_trans->writer_wait, &wait); |
a4abeea4 JB |
1338 | spin_lock(&root->fs_info->trans_lock); |
1339 | root->fs_info->trans_no_join = 1; | |
1340 | spin_unlock(&root->fs_info->trans_lock); | |
13c5a93e | 1341 | } while (atomic_read(&cur_trans->num_writers) > 1 || |
89573b9c | 1342 | (should_grow && cur_trans->num_joined != joined)); |
15ee9bc7 | 1343 | |
3063d29f CM |
1344 | ret = create_pending_snapshots(trans, root->fs_info); |
1345 | BUG_ON(ret); | |
1346 | ||
56bec294 CM |
1347 | ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1); |
1348 | BUG_ON(ret); | |
1349 | ||
2c90e5d6 | 1350 | WARN_ON(cur_trans != trans->transaction); |
dc17ff8f | 1351 | |
e02119d5 CM |
1352 | /* btrfs_commit_tree_roots is responsible for getting the |
1353 | * various roots consistent with each other. Every pointer | |
1354 | * in the tree of tree roots has to point to the most up to date | |
1355 | * root for every subvolume and other tree. So, we have to keep | |
1356 | * the tree logging code from jumping in and changing any | |
1357 | * of the trees. | |
1358 | * | |
1359 | * At this point in the commit, there can't be any tree-log | |
1360 | * writers, but a little lower down we drop the trans mutex | |
1361 | * and let new people in. By holding the tree_log_mutex | |
1362 | * from now until after the super is written, we avoid races | |
1363 | * with the tree-log code. | |
1364 | */ | |
1365 | mutex_lock(&root->fs_info->tree_log_mutex); | |
1366 | ||
5d4f98a2 | 1367 | ret = commit_fs_roots(trans, root); |
54aa1f4d CM |
1368 | BUG_ON(ret); |
1369 | ||
5d4f98a2 | 1370 | /* commit_fs_roots gets rid of all the tree log roots, it is now |
e02119d5 CM |
1371 | * safe to free the root of tree log roots |
1372 | */ | |
1373 | btrfs_free_log_root_tree(trans, root->fs_info); | |
1374 | ||
5d4f98a2 | 1375 | ret = commit_cowonly_roots(trans, root); |
79154b1b | 1376 | BUG_ON(ret); |
54aa1f4d | 1377 | |
11833d66 YZ |
1378 | btrfs_prepare_extent_commit(trans, root); |
1379 | ||
78fae27e | 1380 | cur_trans = root->fs_info->running_transaction; |
5d4f98a2 YZ |
1381 | |
1382 | btrfs_set_root_node(&root->fs_info->tree_root->root_item, | |
1383 | root->fs_info->tree_root->node); | |
817d52f8 | 1384 | switch_commit_root(root->fs_info->tree_root); |
5d4f98a2 YZ |
1385 | |
1386 | btrfs_set_root_node(&root->fs_info->chunk_root->root_item, | |
1387 | root->fs_info->chunk_root->node); | |
817d52f8 | 1388 | switch_commit_root(root->fs_info->chunk_root); |
5d4f98a2 YZ |
1389 | |
1390 | update_super_roots(root); | |
e02119d5 CM |
1391 | |
1392 | if (!root->fs_info->log_root_recovering) { | |
1393 | btrfs_set_super_log_root(&root->fs_info->super_copy, 0); | |
1394 | btrfs_set_super_log_root_level(&root->fs_info->super_copy, 0); | |
1395 | } | |
1396 | ||
a061fc8d CM |
1397 | memcpy(&root->fs_info->super_for_commit, &root->fs_info->super_copy, |
1398 | sizeof(root->fs_info->super_copy)); | |
ccd467d6 | 1399 | |
f9295749 | 1400 | trans->transaction->blocked = 0; |
a4abeea4 JB |
1401 | spin_lock(&root->fs_info->trans_lock); |
1402 | root->fs_info->running_transaction = NULL; | |
1403 | root->fs_info->trans_no_join = 0; | |
1404 | spin_unlock(&root->fs_info->trans_lock); | |
b7ec40d7 | 1405 | |
f9295749 | 1406 | wake_up(&root->fs_info->transaction_wait); |
e6dcd2dc | 1407 | |
79154b1b CM |
1408 | ret = btrfs_write_and_wait_transaction(trans, root); |
1409 | BUG_ON(ret); | |
a512bbf8 | 1410 | write_ctree_super(trans, root, 0); |
4313b399 | 1411 | |
e02119d5 CM |
1412 | /* |
1413 | * the super is written, we can safely allow the tree-loggers | |
1414 | * to go about their business | |
1415 | */ | |
1416 | mutex_unlock(&root->fs_info->tree_log_mutex); | |
1417 | ||
11833d66 | 1418 | btrfs_finish_extent_commit(trans, root); |
4313b399 | 1419 | |
2c90e5d6 | 1420 | cur_trans->commit_done = 1; |
b7ec40d7 | 1421 | |
15ee9bc7 | 1422 | root->fs_info->last_trans_committed = cur_trans->transid; |
817d52f8 | 1423 | |
2c90e5d6 | 1424 | wake_up(&cur_trans->commit_wait); |
3de4586c | 1425 | |
a4abeea4 | 1426 | spin_lock(&root->fs_info->trans_lock); |
13c5a93e | 1427 | list_del_init(&cur_trans->list); |
a4abeea4 JB |
1428 | spin_unlock(&root->fs_info->trans_lock); |
1429 | ||
78fae27e | 1430 | put_transaction(cur_trans); |
79154b1b | 1431 | put_transaction(cur_trans); |
58176a96 | 1432 | |
1abe9b8a | 1433 | trace_btrfs_transaction_commit(root); |
1434 | ||
9ed74f2d JB |
1435 | if (current->journal_info == trans) |
1436 | current->journal_info = NULL; | |
1437 | ||
2c90e5d6 | 1438 | kmem_cache_free(btrfs_trans_handle_cachep, trans); |
24bbcf04 YZ |
1439 | |
1440 | if (current != root->fs_info->transaction_kthread) | |
1441 | btrfs_run_delayed_iputs(root); | |
1442 | ||
79154b1b CM |
1443 | return ret; |
1444 | } | |
1445 | ||
d352ac68 CM |
1446 | /* |
1447 | * interface function to delete all the snapshots we have scheduled for deletion | |
1448 | */ | |
e9d0b13b CM |
1449 | int btrfs_clean_old_snapshots(struct btrfs_root *root) |
1450 | { | |
5d4f98a2 YZ |
1451 | LIST_HEAD(list); |
1452 | struct btrfs_fs_info *fs_info = root->fs_info; | |
1453 | ||
a4abeea4 | 1454 | spin_lock(&fs_info->trans_lock); |
5d4f98a2 | 1455 | list_splice_init(&fs_info->dead_roots, &list); |
a4abeea4 | 1456 | spin_unlock(&fs_info->trans_lock); |
e9d0b13b | 1457 | |
5d4f98a2 YZ |
1458 | while (!list_empty(&list)) { |
1459 | root = list_entry(list.next, struct btrfs_root, root_list); | |
76dda93c YZ |
1460 | list_del(&root->root_list); |
1461 | ||
1462 | if (btrfs_header_backref_rev(root->node) < | |
1463 | BTRFS_MIXED_BACKREF_REV) | |
3fd0a558 | 1464 | btrfs_drop_snapshot(root, NULL, 0); |
76dda93c | 1465 | else |
3fd0a558 | 1466 | btrfs_drop_snapshot(root, NULL, 1); |
e9d0b13b CM |
1467 | } |
1468 | return 0; | |
1469 | } |